The present invention generally relates to novel therapeutic compounds, pharmaceutical compositions containing such compounds, methods for preparing such compounds and methods for using these compounds, alone or in combination with other therapeutic agents, for the treatment and prevention of symptoms or manifestations (e.g., inflammation) associated with disorders affected by Interleukin-12 (xe2x80x9cIL-12xe2x80x9d) intracellular signaling, such as, for example, Th1 cell-mediated disorders.
Inflammatory responses are a component of the pathogenesis of many vertebrate disorders/diseases, including those in humans. In its broadest meaning, the term xe2x80x9cinflammationxe2x80x9d denotes local as well as systemic responses. Increased blood flow, vasodilation, fluid transudation from the vessels, infiltration of the tissues by leukocytes and, in some severe cases, intravascular thrombosis, damage to the blood vessels and extravasation of blood characterize local inflammation. The systemic inflammatory response, also denoted as an acute phase response, is characterized by various reactions including, for example, fever, leukocytosis and release of acute phase reactants into the serum. In severe cases, shock and death may occur. See Heremans et al., Lymphokine Research 8(3): 329-333 (1989). Diseases involving inflammation are particularly harmful when they afflict the respiratory system, resulting in obstructed breathing, hypoxemia, hypercapnia and lung tissue damage. Obstructive diseases of the airways are characterized by airflow limitation (i.e., airflow obstruction or narrowing) due to constriction of airway smooth muscle, edema and hypersecretion of mucous leading to increased work in breathing, dyspnea, hypoxemia and hypercapnia. While the mechanical properties of the lungs during obstructed breathing are shared between different types of obstructive airway diseases, the pathophysiology can differ.
The inflammatory response is believed to be controlled by a variety of cellular events characterized by the influx of certain cell types and mediators, the presence of which can lead to tissue damage and sometimes death. For example, cytokines are primary factors in the biochemical cascade of events that regulate inflammatory responses. Some cytokines induce or release other known mediators of inflammation. These systems are controlled by related feedback mechanisms. Thus, it is believed that inflammatory responses are not a result of a single cytokine being released in large quantities, but rather to a set of cytokines collectively acting via a network of intercellular signals to incite the inflammatory response.
One particular cytokine, IL-12, also referred to as natural killer cell stimulatory factor (xe2x80x9cNKSFxe2x80x9d) or cytotoxic lymphocyte maturation factor (xe2x80x9cCLMFxe2x80x9d), is a potent immunoregulatory molecule that plays a role in a wide range of diseases. In particular, IL-12 is a heterodimeric cytokine that is produced by phagocytic cells, e.g., monocytes/macrophages, B-cells and other antigen-presenting cells (xe2x80x9cAPCxe2x80x9d) and is believed to act as a proinflammatory cytokine. IL-12 is believed to play a specific role in diseases exhibiting an inflammatory component, namely, diseases that exhibit cell-mediated inflammatory responses, such as, multiple sclerosis, diabetes, chronic inflammatory bowel disease, etc.
IL-12 affects both natural killer cells (xe2x80x9cNK cellsxe2x80x9d) and T-lymphocytes (xe2x80x9cT cellsxe2x80x9d), and stimulates IFN-xcex3 production by both of these cell types. For example, in NK cells, IL-12 stimulates: NK cell proliferation, membrane surface antigen up-regulation, LAK cell generation and NK cell activity elevation; induces IFN-xcex3 and IFN-xcex1 production and the growth and expansion of either resting or activated NK cells; and increases soluble p55 and soluble p75 TNF receptor production and NK cell cytotoxicity. See RandD Systems Catalog, pp. 67-69 (1995). T cells recognize antigens via interaction of a heterodimeric (alpha/beta, or gamma/delta) receptor with short peptide antigenic determinants that are associated with major histocompatibility complex (xe2x80x9cMHCxe2x80x9d) molecules. T cells can be divided broadly into two functional categories by the presence of two mutually exclusive antigens on their cell surface, CD4 (helper) and CD8 (cytotoxic). The CD4 and CD8 antigens regulate T cell interaction with MHC and their mutually exclusive expression derives from their strict specificity for MHC. Class II MHC-restricted T cells are primarily CD4+ and class I MHC-restricted T cells are CD8+. The T cells further differentiate into helper, cytotoxic and suppressor cells.
As mentioned above, IL-12 also affects T cells, including stimulation of T cell IFN-xcex3 production in response to antigen. While CD8+ T cells are associated with cytotoxicity functions, CD4+ T cells are associated with helper function and secrete various cytokines that regulate and modulate immune responses. CD4+ T cells can be further subdivided into T helper 1 (Th1) and T helper 2 (Th2) subsets, according to the profile of cytokines they secrete. Therefore, Th1 cells produce predominantly inflammatory cytokines, including IL-2, TNF-xcex1 and IFN-xcex3, while Th2 cells produce anti-inflammatory cytokines such as IL-4, IL-5, IL-10, and IL-13 that are linked to B cell growth and differentiation.
The Th1 and Th2 CD4+ T cell subsets are derived from a common progenitor cell, termed Th0 cells. During an initial encounter with an antigen, the differentiation into Th1 and Th2 is controlled by the opposing actions of two key cytokines, namely IL-12 and IL-4, which induce the differentiation of Th0 into Th1 and Th2, respectively. The development of Th1 and Th2 cells is primarily influenced by the cytokine milieu during the initial phase of the immune response, in which IL-12 and IL-4, respectively, play decisive roles. The cytokines produced by each Th-cell phenotype are inhibitory for the opposing phenotype. For example, Th1 cytokines enhance cell-mediated immunities and inhibit humoral immunity. Th2 cytokines enhance humoral immunity and inhibit cell-mediated immunities. Trembleau et. al., See Immunology Today 16(8): 383-386 (1995).
Furthermore, CD4+ Th1 cells play a role in the pathogenesis of immunological disorders. These cells primarily secrete cytokines associated with inflammation such as IFN-xcex3, TNF-xcex1, TNF-xcex2 and IL-2. IFN-xcex3 is an important component of the inflammatory response and resultant pathology of those diseases exhibiting an inflammatory response. Heremans, et al. In addition to its role in inflammatory response, IFN-xcex3 also contributes to phagocytic cell activation (i.e., macrophage activation), and up-regulation of MHC expression on the surface of antigen-presenting cells (xe2x80x9cAPCxe2x80x9d) and other cells. Further, this cytokine is implicated generally in inflammatory immune responses, and in autoimmune diseases, such as multiple sclerosis (xe2x80x9cMSxe2x80x9d), specifically. See Owens et al., Neurologic Clinics, 13(1):51-73 (1995). Furthermore, steroid treatment broadly attenuates cytokine production, but it cannot modulate it selectively, e.g., just the Th0, the Th1 or the Th2 pathways.
IL-12 plays a role in the induction of Th1-cell-mediated autoimmunity. Recent evidence points to a critical role for IL-12 in the pathogenesis of rodent models of Th1-mediated autoimmune diseases such as type-1 diabetes, multiple sclerosis, rheumatoid arthritis, inflammatory bowel disease, and acute graft-versus-host disease. Thus, Th1 cells are believed to be involved in the induction of experimental autoimmune diseases, as demonstrated in adoptive transfer experiments demonstrating the CD4+ cells producing Th1-type lymphokines can transfer disease, as shown in models of experimental autoimmune disease, such as experimental allergic encephalomyelitis (xe2x80x9cEAExe2x80x9d) (also known as experimental allergic encephalitis) and insulin-dependent diabetes mellitus (xe2x80x9cIDDMxe2x80x9d). See Trinchieri, Annu. Rev. Immunol. 13(1):251-276 (1995). For instance, EAE is an inflammatory T cell mediated, paralytic, demyelinating, autoimmune disease that can be induced in a number of rodents as well as primates. Owens et al. One of the ways that EAE can be induced is by immunization of animals with myelin basic protein (xe2x80x9cMBPxe2x80x9d). Likewise, administration of IL-12 induces rapid onset of IDDM in 100% of NOD female mice. Trinchieri. Thus, one goal of immunotherapy research and development efforts has been to limit inflammatory response while leaving the specificity of the immune system, deemed necessary for host protection, in tact.
For example, steroid therapy is the most common treatment for one such IL-12 mediated disease, MS, particularly, corticosteroids. This suggests that steroids alter the trafficking of cells into the brain or reduce the secretion of cytokines by inflammatory cells in areas of inflammation. Although their effect in reversing some of the acute symptoms of autoimmune disease, such as MS, are well known, their side effects have precluded long-term use.
Other treatments that target immune system components include lymphocyte cytotoxic drugs such as cyclophosphamide and azathioprine. These drugs act like xe2x80x9csledgehammersxe2x80x9d in that they suppress the entire immune system and raise problems that attend broad-spectrum immunosuppression therapies. The same problems also are likely with newer therapies such as cyclosporine, anti-CD4 monoclonal antibodies, and others. Other treatments for IL-12 mediated diseases, including MS, can involve the administration of anti-IL-12 antagonists such as antibodies. Anti-IL-12 antibodies have been shown to inhibit the development of IDDM and EAE. See Trinichieri. However, antibody based immunotherapy may result in immune complex formation and deposition, thus leading to glomerulonephritis, vasculitis and arthritis.
Moreover, symptomatic treatment with beta-agonists, anticholinergic agents and methyl xanthines have been clinically beneficial for the relief of discomfort but fail to stop the underlying inflammatory processes that cause the disease. The frequently used systemic glucocorticosteroids have numerous side effects, including, but not limited to, weight gain, diabetes, hypertension, osteoporosis, cataracts, atherosclerosis, increased susceptibility to infection, increased lipids and cholesterol, and easy bruising. Aerosolized glucocorticosteroids have fewer side effects but can be less potent and have side effects, such as thrush.
The use of anti-inflammatory and symptomatic relief reagents is a serious problem because of their side effects or their failure to attack the underlying cause of an inflammatory response. Other anti-inflammatory agents, such as cromolyn and nedocromil are much less potent and have fewer side effects. Anti-inflammatory agents that are primarily used as immunosuppressive agents and anti-cancer agents (i.e., cytoxan, methotrexate and Immuran) have also been used to treat inflammation. These agents, however, have serious side effect potential, including, but not limited to, increased susceptibility to infection, liver toxicity, drug-induced lung disease, and bone marrow suppression. Thus, such drugs have found limited clinical use, for example, in the treatment of most airway hyperresponsiveness lung diseases.
Accordingly, there remains a need for novel therapeutic compounds and methods that inhibit the deleterious effects of inflammatory responses mediated by specific cytokines, such as IL-12, without adversely affecting the other components of the immune system that are deemed necessary for protecting the host and without the attendant disadvantages of conventionally available compounds and methods.
It is an object of the present invention to provide novel therapeutic compounds, including pharmaceutical compositions thereof and methods useful for inhibiting IL-12 signaling in a mammal having, for example, an inflammatory response.
It is another object of the present invention to provide novel therapeutic compounds, pharmaceutical compositions thereof and methods that are capable of limiting the inflammatory response of a subject without adversely affecting the specificity of the immune system deemed necessary for protecting the subject.
The above and other objects are accomplished by a compound, pharmaceutically acceptable derivatives (e.g., racemic mixtures, resolved enantiomers, diastereomers, tautomers, salts and solvates thereof) or prodrugs thereof, having the following Formula I: 
wherein:
the dashed lines, i.e., xe2x80x9cxe2x88x92-xe2x88x92-xe2x88x92-xe2x80x9d, in Formula I represent either a single or double bond;
X, Y and Z are independently selected from a member of the group consisting of C(R3), N, N(R3) and S;
R1 is selected from a member of the group consisting of hydrogen, methyl, C(5-9)alkyl, C(5-9)alkenyl, C(5-9)alkynyl, C(5-9)hydroxyalkyl, C(3-8)alkoxyl, C(5-9)alkoxyalkyl; and
R2 and R3 are independently selected from a member of the group consisting of hydrogen, halo, oxo (keto), C(1-20)alkyl, C(1-20)hydroxyalkyl, C(1-20)thioalkyl, C(1-20)alkylamino, C(1-20)alkylaminoalkyl, C(1-20)aminoalkyl, C(1-20)aminoalkoxyalkenyl, C(1-20)aminoalkoxyalkynyl, C(1-20)diaminoalkyl, C(1-20)triaminoalkyl, C(1-20)tetraaminoalkyl, C(5-15)aminotrialkoxyamino, C(1-20)alkylamido, C(1-20)alkylamidoalkyl, C(1-20)amidoalkyl, C(1-20)acetamidoalkyl, C(1-20)alkenyl, C(1-20)alkynyl, C(3-8)alkoxyl, C(1-11)alkoxyalkyl, and C(1-20)dialkoxyalkyl.
R1 is optionally substituted with a member of the group consisting of Nxe2x80x94OH, cyano (e.g., NCxe2x80x94), cyanamido (e.g., NCNHxe2x80x94), cyanato (e.g., NCOxe2x80x94), sulfo, sulfonyl, sulfinyl, sulfhydryl (mercapto), sulfeno, sulfanilyl, sulfamyl, sulfamino, and phosphino, phosphinyl, phospho, phosphono.
Each R2 and R3 is optionally substituted with one or more members of the group consisting of hydroxyl, methyl, carboxyl, furyl, furfuryl, biotinyl, phenyl, naphthyl, amino group (e.g., xe2x80x94NH2), amido group (e.g., xe2x80x94C(xe2x95x90O)Nxe2x80x94), carbamoyl group (e.g., H2NCOxe2x80x94), cyano (e.g., NCxe2x80x94), cyanamido (e.g., NCNHxe2x80x94), cyanato (e.g., NCOxe2x80x94), sulfo, sulfonyl, sulfinyl, sulfhydryl (mercapto), sulfeno, sulfanilyl, sulfamyl, sulfamino, phosphino, phosphinyl, phospho, phosphono, Nxe2x80x94OH, xe2x80x94Si(CH3)3, C(1-3)alkyl, C(1-3)hydroxyalkyl, C(1-3)thioalkyl, C(1-3)alkylamino, benzyldihydrocinnamoyl group, benzoyldihydrocinnamido group, heterocyclic group and carbocyclic group.
The heterocyclic group or carbocyclic group is optionally substituted with one or more members of the group consisting of halo, hydroxyl, nitro (e.g., xe2x80x94NO2), SO2NH2, C(1-6)alkyl, C(1-6)haloalkyl, C(1-8)alkoxyl, C(1-11)alkoxyalkyl, C(1-6)alkylamino, and C(1-6)aminoalkyl.
Preferably, both X and Y are not N(R3) when Z is C(R3) and R3 is H or C(1-3)alkyl.
More preferably, R1 is not an xcfx89-1 secondary alcohol substituted C(5-8)alkyl when both X and Y are N(R3), Z is C(R3) and R3 is H or C(1-3)alkyl.
In a further aspect, the present invention is directed to a method for inhibiting a cellular process or activity mediated by IL-12, the method comprising:
(a) contacting IL-12 responsive cells with a compound of the present invention, as described herein; and
(b) determining that the cellular process or activity mediated by IL-12 is inhibited.
In a still further aspect, the present invention is directed to a method for treating a Th1 cell-mediated inflammatory response in a mammal in need of such treatment, the method comprising:
administering to the mammal a therapeutically effective amount of the compound of the present invention, wherein said compound is capable of inhibiting an IL-12 mediated cellular process or activity, thereby inhibiting the inflammatory response.
In accomplishing the above and other objects, the present invention provides novel therapeutic compounds and methods for affecting, inter alia, the inflammatory response associated with Th1 cell-mediated diseases, without affecting the other components of the immune system that are deemed necessary for host protection. The compounds and methods of the present invention are characterized by their ability to inhibit IL-12 signaling. Without wishing to be bound by theory, it is believed that the therapeutic compounds of the present invention short-circuit the inflammatory cascade by inhibiting IL-12-dependent Th1 development, emphasizing the present invention""s importance in disease therapy by inhibiting IL-12 signaling in the regulation of Th1-mediated inflammatory disorders. Inhibition of IL-12 signaling decreases the production of IFN-xcex3, thus mitigating the inflammatory response in disease conditions mediated by Th1 cells. Specifically, the present invention may impede signaling that induces differentiation of T cells to Th1 cells. In general, differentiated Th1 cells produce high levels of IFN-xcex3, which provokes inflammation, a component of many disease conditions that the inventive compounds and methods target.
The present invention achieves the above and other objects by, inter alia, providing novel therapeutic compounds and methods for treating or preventing IL-12 or Th1 mediated symptoms (e.g. inflammation) of diseases that include, without limitation, (1) inflammatory diseases or disorders, such as, for example, arthritis, asthma, chronic inflammatory diseases, chronic intestinal inflammation, psoriasis, septic shock, septicemia, and adult respiratory distress syndrome; (2) autoimmune diseases or disorders, such as, for example, acute and chronic graft-versus-host disease, autoimmune gastritis, autoimmune hemolytic anemia, autoimmune neutropenia, chronic active hepatitis, chronic thyroiditis, inflammatory bowel disease (e.g., Crohn""s Disease and ulcerative colitis), lupus disorders (e.g. systemic lupus erythematosus), multiple sclerosis, myasthenia gravis, rheumatoid arthritis, scleroderma, thrombocytopenia, thyroid diseases (e.g., Graves"" and Hashimoto""s disease), type-1-IDDM, and uveitis; and (3) neurodegenerative diseases such as, for example, amyotrophic lateral sclerosis, Alzheimer""s disease, Parkinson""s disease, and primary lateral sclerosis. The compounds of the present invention may be employed in any suitable conventional manner for the treatment of the above diseases. Such methods of treatment, their dosage levels and requirements may be selected by those of skill in the art from available methods and techniques that are further described below, that are known in the art or that are readily determinable using routine experimentation.
The compounds of the present invention will also be useful for inhibiting IL-12 mediated signaling in other applications such as in vitro systems and in vivo animal models of IL-12 mediated diseases. Accordingly, the present invention encompasses a kit comprising a compound of the present invention, as described herein, for use in such applications.
Additional aspects, embodiments and advantages of the present invention will be set forth, in part, in the description that follows, or may be learned from practicing or using the present invention. The objects and advantages may be realized and attained by means of the features and combinations particularly pointed out throughout this description and the appended claims. It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not to be viewed as being restrictive of the invention as claimed.